Adjustable length pipe coupling



Nov. 20, 1951 R. L. SHUGART ETAL 2,575,685

ADJUSTABLE LENGTH PIPE COUPLING Filed Dec. 18, 1947 RALPH LEROY SHUGART ALFRED H. STROMEIER E www Patented Nov. 20, n1951 OFFICE ADJUSTABLE LENGTH PIPE COUPLING Ralph Leroy Shugart, Warren, and AlfredH. Stromeier, Youngstown, Ohio Application December 18, 1947, Serial No. 792,514

This invention relates to improvements in pipe couplings and more particularly, to new and useful improvements in the design and construction of pipe couplings of variable length. The practical embodiments of the invention which are in the nature of pipe-unions have particular utility, as will be well understood by those familiar with the art, in connecting two pieces of pipe in end-to-end relation. Devices constructed according to the present invention are further advantageous in that the spacing between the two pieces of pipe to be connected need not be xed, but may be variable as circumstances require.

It is the primary object of our invention to provide an improved pipe coupling of the general character specied above, which is exceedingly simple in design, economical to produce, and capable of being installed in conventional piping systems with the aid of tools normally employed in the pipe-tters trade. A more speciiic object of the invention is the provision of an improved variable pipe length coupling which, while offering a minimum of resistance to the iiow of iiuid through a connected pipe line, is yet of minimum over-al1 or outside diameter,whereby the outward appearance and convenience of the coupling of the invention is enhanced.

Another object of the invention is the provision of an improved fluid tight joint for pipe couplings and the like. In accordance with this aspect of our invention, a mechanical joint is made between an internally threaded member and an externally threaded member iitting therein, and a recess is provided in a portion of the first mentioned member to receive a compressible sealing ring, which by means of a gland nut threaded on to the second mentioned member, is compressed into tight engagement with the threads of the second mentioned member, and simultaneously into pressure contact with an annular surface of the recess to thereby provide an effective seal about the mechanical joint. The interlocking of the material of the sealing ring with the threads of one of the tubular members of. the coupling is most eiective in not only sealing the joint against the escape of fluid, but in also resisting loosening ofthe parts.

A still further object of the invention is the provision of a materially simpliiied pipe-union or coupling for high-pressure conduit application. By the use of a screw-threaded interconnection of substantial axial length between two relatively adjustable parts of the coupling, adequate mechanical strength is imparted and 1 claim. (C1. 285-199) through the use of an improved packing gland between these parts, the escape of fluid is prevented even in the presence of severely high pressures.

The above and other objects and advantages of the invention will become apparent upon the consideration of the following detailed specification and the accompanying drawing, wherein there is disclosed a preferred embodiment of the invention.

In the drawing:

Figure 1 is an exploded view, partly in section and partly in elevation, of a variable pipe-length coupling constructed in accordance with the principles of our invention; and,

Figure 2 is a longitudinal section of an assembled coupling constructed in accordance with the teaching of our invention.

Referring to the drawing in detail, the reference numeral I0 designates generally a tubular member which has an end portion of reduced internal diameter provided with the pipe-threads II. As suggested in Figure 2, the member I9 may, by means of the threads II, be rigidly attached to the threaded end of a conventional pipe-length which is to be connected by the couplings now being described. Tubular member I 0 has a second and axially spaced portion of reduced internal diameter in which` is incorporated screw-threads I2. It should be noted that the screw-threads I2 are spaced axially inward of the end of the member IU, which is opposite the threaded end thereof, to provide an annular recess I3, for the recession of a compressible sealing ring as will appear more in detail below:

Adapted to be partially received in the tubular member I0 is a second tubular member I4 in the nature of a determinate length of conventional pipe and a substantial portion of one end of the member I4 is exteriorly screw-threaded as shown at I5. Threads I5 are complementary to the threads I2 of the member I0 so that the member I4 may be screwed into the member I0, a variable extent, as circumstances require. The opposite end of the member I4 is exteriorly threaded, as shown at I6 for connection with a conventional interiorly threaded sleeve type of pipe coupling which may be fastened onto the end of a second conventional pipe length to be connected.

We prefer to make the lead of all the pipe and screw threads of the assembly identical and to make all these threads of the same direction so that in applying the coupling of the invention to existing piping installations it is not necessary to axially shift any of the pipes to be connected.

Thus, by referring to Figure 2 it will be noted that if the member I is run up on the member I 4, a maximum extent, the member I4 may be threaded into the conventional pipe coupling above described or. into any other fitting having appropriate female threads and in so doing, the member I0 may be axially aligned with the pipe or other fitting to be inter-connected thereby.

Now by rotating the -member I 0 on the member I4 the member I I3 will be caused to move outwardly along the member I4 and to simultaneously be threaded on to the male threaded part of the pipe or other fitting to be connected; It should readily be understood that inthe practice of the invention the member I4 may beifurnished inLdi-fferent lengths or it may be of a long standard length, in which case the screw threaded end thereof may be cut oi to any length desired.

Received within the recess I3 is a compressible sealing ring I I, which is arranged to be axially -compressed Vby 'the gland nut I8 which is threaded on the screw threads I5. As shown in the drawing, the screw threaded interconnection between the member i4 and the nut I8 is of substantial axiallength, and this feature co-acting with the substantial axial length of the screw threads I2 allows the nut I8 to be pulled down very tightly, thereby subjecting the material of the ring Il to a heavy compressive force, which causes the material to flow radially inward and outward into tight engagement with the screw threa'dsi .and theA outer wall of the recess i3, respectively. In this manner a most effective seal is obtained which is operative to withstand either low or high pressures. if desired, a lock nut 119 may be provided for the packing gland nut I8.V

It should now be apparent that we have provided 'an improved adjustable length pipe couplinff which accomplishes .the objects initially set out. The coupling of the invention is extremely simple 'in design, requiring but three major parts, any and .all of which may be expeditiously and economically produced on automatic machinery of conventional design. The coupling may be readily installed and when installed, presents a minimum of resistance to the iiow of fluid through it and the connected pipe lengths. Also, the exterior of the coupling'is of pleasing design, and of minimum dimension, thereby enabling the coupling to be used in many circumstances where the installation of'more conventional couplings may be impossible or undesirable.

It should also be particularly noted that the screw threads I2 and 'I5 of the parts I 0 and i 4,

respectively, are of the straight or machine variety as distinguished from tapered pipe threads so that the member I4 may be screwed into member Il! a widely varying extent. This provides for considerable adjustment in the length of a coupling formed of any particular sizes of members II) and I4 and, further, enables a strong iluidtie'ht joint to be made between the spaced opposed ends of two pipe lengths without moving the pipe lengths in any direction and without setting up any stresses whatever in said lengths.

rlhe above specically described embodiments of the invention should be considered as illustrative only asobviously many changes may be made therein Without departing from the spirit or scope of the invention. Reference should therefore be had to the appended claim in determining the scope of the invention.

We claim:

An adjustable length pipe coupling comprising in combination a tubular member having conventionalinternal 'tapered pipe threads 'at one end and having conventional machine threads of uniform diameter adjacent its opposite end portion, said tubular member being of enlarged internal diameter intermediate said pipe threads and said .machine threads, said opposite end portion having a larger internal diameter than the internal diameter of the machine-threaded portion to provide an annular recess, a compressible sealing ring in said recess, a second'tubular member externally machine-threaded at one end for engagement with the internally machine-threaded portion' of saidiirst mentioned tubular membe Y and externally pipe-threaded at its opposite end',- saidmachine threads Aand said pipe threads haveing substantiallyL the same pitch, and a packing gland nut threaded on the machine-threaded portion of'sa'id second tubular member and adaptedto enter 'said recess to compress the sealing ring'therein.

RALPH LEROY SHUGART. ALFRED H. STROMEIER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 438,752 'Lawson Oct. 21, 1890 1,955,831 Raybould Apr. 24, 1934 2,448,232 Muse Aug. 31, 1948 FOREIGN PATENTS Number Country Date 2931574 GreajtIBritan July 12, V1928 

